Related papers: Magnetic droplets in a metal close to a ferromagne…
In ordinary metals, antiferromagnetic exchange between conduction electrons and a magnetic impurity leads to screening of the impurity spin below the Kondo temperature, $T_K$. In systems such as semimetals, small-gap semiconductors and…
We investigate the Kondo effect in two-dimensional disordered electron systems using a finite-temperature quantum Monte Carlo method. Depending on the position of a magnetic impurity, the local moment is screened or unscreened by the spin…
We study the effect of the disorder on the metallic behavior of a two-dimensional electron system in silicon. The temperature dependence of conductivity $\sigma (T)$ was measured for different values of substrate bias, which changes both…
We consider the effect of potential disorder on magnetic properties of a two-dimensional metallic system (with conductance $g\gg 1$) when interaction in the triplet channel is so strong that the system is close to the threshold of the…
We present theoretical studies of temperature dependent diamagnetic-paramagnetic transitions in thin quantum rings. Our studies show that the magnetic susceptibility of metal/semiconductor rings can exhibit multiple sign flips at…
We present a field theory for a structurally disordered magnetic system coupled to a metallic environment near a quantum critical point. We show that close to the magnetic quantum critical point droplets are formed due to the disorder and…
We report thermodynamic magnetization measurements of two-dimensional electrons in several high mobility Si metal-oxide-semiconductor field-effect transistors. We provide evidence for an easily polarizable electron state in a wide density…
We report temperature and density dependences of the spin susceptibility of strongly interacting electrons in Si inversion layers. We measured (i) the itinerant electron susceptibility $\chi^*$ from the Shubnikov-de Haas oscillations in…
We study the physics of dilute magnetic impurities in a two-dimensional altermagnetic metal. For the single impurity case, although the spin degeneracy is broken in an altermagnetic metal, we show that the antiferromagnetic Kondo coupling…
A model recently introduced for diluted magnetic semiconductors by Berciu and Bhatt (PRL 87, 107203 (2001)) is studied with a Monte Carlo technique, and the results are compared to Hartree-Fock calculations. For doping rates close to the…
We present a theory of a single point, line or plane defect coupling to the square of the order parameter in a metallic system near a quantum critical point at or above its upper critical dimension. At criticality, a spin droplet is…
We investigate magnetic properties induced by a spinless impurity in strongly correlated electron systems, i.e. the Hubbard model in the spatial dimension $D=1,2,$ and 3. For the 1D system exploiting the Bethe ansatz exact solution we find…
We apply the classical mapping technique developed recently by Dharma-wardana and Perrot for a study of the uniform two-dimensional electron system at arbitrary degeneracy and spin-polarization. Pair distribution functions, structure…
Dynamic magnetic susceptibility, $\chi$, was studied in several intermetallic materials exhibiting ferromagnetic, antiferromagnetic and metamagnetic transitions. Precise measurements by using a 14 MHz tunnel diode oscillator (TDO) allow…
Recent experiments on the amorphous magnetic semiconductor Gd_x Si_{1-x}, Phys. Rev. Lett. 77, 4652 (1996), ibid 83, 2266 (1999), ibid 84, 5411 (2000), ibid 85, 848 (2000), have revealed an insulator-metal transition (i-m-t), as a function…
Systematically magnetic and magnetothermal measurements at temperatures down to 2 K and magnetic fields up to 13.5 Tesla for Gd(OH)3 Single Crystal Nanowires - Quasi-1D Large Spin (S = -7/2) Chain Antiferromagnet have been conducted. We…
Recent thermodynamic measurements on two-dimensional (2D) electron systems have found diverging behavior in the magnetic susceptibility and appearance of ferromagnetism with decreasing electron density. The critical densities for these…
Ferromagnetism is an exciting phase of matter exhibiting strongly correlated electron behavior and a standard example of spontaneously broken rotational symmetry: below the Curie temperature, atomic magnets in an isotropic single-domain…
The magnetic resonance spectrum of spin clusters formed in spin-Peierls magnets in the vicinity of impurity ions was investigated. The observed temperature dependences of the effective g-factor and the linewidth of the electron spin…
We study ferromagnetic transition in three-dimensional double-exchange model containing impurities. The influence of both spin fluctuations and impurity potential on conduction electrons is described in coherent potential approximation. In…